thanks
OxWall does not work well, not most plugins with PHP 7.2, ask your server to install PHP 5.x and you will not have problems.
Perhaps in your control panel of your servers you have the possibility to change the PHP version
Using more modern versions of PHP does not give you anything extra because the new features that it incorporates are not used in OxWall, perhaps it will provide some speed but it would need a very accurate chronometer to appreciate it because the slowness of OxWall is due to the queries to the database and not the calculation.
Gami, please wait for the OxUpdater patch. I've already told you this is directly related to the Smarty libraries and has ALREADY been fixed and it is merely a warning, not an error.
Please see this:
https://developers.oxwall.com/forum/topic/63913
I am exhausted, but I will have a patch shortly...
For the Record, Oxwall and actually every bit of my site is much quicker on PHP 7.2 for me, not just Oxwall.